HP 6038A  DOA, troubleshooting, FIXED - Page 1
Forum section: electronics / repair

author: valley001
author_rank: Frequent Contributor
timestamp: October 13, 2020, 08:20:17 pm
content: Hello all,I found myself in need of a smallish power supply and learned of these system power supplies made by HP. I really like the quality of the older HP gear so I searched one out.I will not have my example until I pick it up next week. It "does not power up" so I welcome informed guesses on potential avenues of investigation. I have the service manual and plan to follow the flow chart there, as a start. Anyone have experience with these? I see limited info out there aside from some general commentary. As I improve my troubleshooting skills I have become less inhibited re the purchase of dead units, hopefully that does not bite me with this one

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 14, 2020, 01:05:51 am
content: Hi,First of all you can get the service manual directly from the Keysight website. Search for 6033A, the 6033A and the 6038A share the same Service Manual.These supplies share a lot of the circuitry found in the 6024A. You can read about the 6024A here:https://www.hpl.hp.com/hpjournal/pdfs/IssuePDFs/1981-08.pdfTroubleshootingBefore I get into the details, these power supplies are off-line switching supplies. A large portion of the circuit is connected directly to the line. Read and understand all the warnings in the HP Service Manual before attempting repair of these units.The nature of this circuit, is that if you don't repair everything, it will fail catastrophically again. It is very important to find all the damaged components.First I would do a visual inspection. Check the electrolytic capacitors, especially in the bias supply have not leaked and corroded all the tracks on the board.You can also check the main power MOSFETs.If the MOSFETs are damaged you will probably have to rebuilt all the circuitry on the gates.Have a look at this thread:https://www.eevblog.com/forum/testgear/hp6012a-1kw-power-supply-repair/msg1019892/#msg1019892Hard to give more advice until the unit arrives.Jay_Diddy_B

author: coromonadalix
author_rank: Super Contributor
timestamp: October 14, 2020, 01:17:06 am
content: yep As Jay wrote do a visual check for fuse(s) power switch ....This psu is one tough cookie, if everything seems visually fine, i would isolate the main board from the power mesh section, hoping to test all the bias power supplyCareful you will have two ground levels in this psu, the high voltage ground on the input rectifier 4a 4c, and the "low power section" bias power supply triangle 1 and 3 after the r50 0.7 ohmsIt must be like a floating supply sectionOn the input filter section 12a, 12c with 4a, 4c you will have a high voltage 240v and up be carefulFollow the service manual trouble shooting section

author: valley001
author_rank: Frequent Contributor
timestamp: October 14, 2020, 01:39:16 am
content: Thank you both for the insight. I am studying the service manual/schematics and learning as much as I can about this unit. I will plan to do a visual inspection and perhaps some testing of caps. Look for discoloration etc.I assume if a fuse is blown I am in for some fun. I see two fuses on the A8 board along with the primary fuse on the back panel.

author: valley001
author_rank: Frequent Contributor
timestamp: October 19, 2020, 03:13:47 am
content: I now have the unit in hand. It is in fairly good shape cosmetically, nothing obviously toasted and I believe I am the first one to open it up.F2 on the main board blows immediately when the power is applied.I checked the 120v winding on T3 and it seems ok, 8-9 ohms or so. Further testing of the main board may require additional disassembly. My plan next is to test the filter caps, rectifier diodes etc. Anything else I should look at?

author: valley001
author_rank: Frequent Contributor
timestamp: October 19, 2020, 08:30:41 pm
content: I removed the A4 power mesh board and attempted to apply power with a fresh F2, it blows immediately.F1 and 2 on A4 are intact, the FETs seem to be OK. No obviously blown components there.There is an audible buzzing coming from the IEC socket when the power cord is installed. R20 and 21 are getting warm (not much but noticeably more than the surrounding components, up to maybe 90 deg F. This is all with the power switch in the off position and F2 empty. I have checked C2-4 filters in situ and they are at least not a dead short, they test 400-900uf with my DMM.I am thinking my problem is on the A1 main board, wondering if you all agree before I disassemble further (removing A1 for complete access requires total disassembly of the unit, more or less).

author: George Edmonds
author_rank: Frequent Contributor
timestamp: October 19, 2020, 08:39:55 pm
content: HiBuzzing IEC's are not uncommon, at lot of Chinese ones are not made to the correct dimensions and make a poor contact.Your best move is to put a 100W incandescent bulb is series with the incoming phase, this prevents instant fuse blowing. BE AWARE THAT THERE IS SOME 360VDC AT LOW IMPEDANCE THROUGHOUT THE HIGH VOLTAGE SECTION, THIS WILL KILL YOU.George G6HIG

author: bdunham7
author_rank: Super Contributor
timestamp: October 19, 2020, 08:47:45 pm
content: I'd think you'd want to pull out or disconnect the control board to see if the short is in the rectifiers or transformer section on the main board or further down the line on the control board.

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 01:01:49 am
content: Yes, disconnecting the A4 and A2 boards still results in a blown fuse. I do need to fab up a dim bulb tester so I stop blowing them.I have been testing through the components on the A1 board. All of the diodes seem OK. I have checked most of the windings on T3 and the readings seem reasonable, 9 ohms for the primary for instance. The caps I suppose will require removal, none measure a dead short they all register capacitance on my DMM. Is there a way to narrow down a bad cap short of disordering them? Hate to de solder when I don't have to, especially with these really nice HP PCBs.EDIT- I also checked the fan motor winding and it measures around 215 ohms.I do appreciate the input.

author: George Edmonds
author_rank: Frequent Contributor
timestamp: October 20, 2020, 02:00:39 am
content: HiWhere are you in the world and what is your mains voltage?Personally I would pull the A1 board and do a DC resistance check across what looks like R9 1M, the schematic that I have is of poor quality. If not short circuit then apply mains with a 100W or lower wattage incandescent bulb in series across R9 DO NOT DO THIS WITHOUT THE BULB IN SERIES as there will be no fuse present. It is not clear from the schematic as to how line module connects to the A1 board.If the bulb flashes on power up and then goes dim of goes out all is well with the A1 board, if it remains at full brilliance you have a fault on the A1 board.Leave A1 board for some time before handling it to allow main capacitors to discharge via R20/R21 and then check with DMM that there is no voltage present across R20/R21George G6HIG

author: George Edmonds
author_rank: Frequent Contributor
timestamp: October 20, 2020, 02:11:23 am
content: HiHaving looked further at the manual the A1 board is the mother board, just pull all other boards and cary out my suggested tests.George G6HIG

author: bdunham7
author_rank: Super Contributor
timestamp: October 20, 2020, 02:17:48 am
content: This is where the iso-variac earns its keep.With A2 and A4 removed, there doesn't seem to be much left. Measure the resistance across C26 with F2 out, that should be your primary resistance. If that is low, check C26 and the voltage selection switches. Also test between both sides and ground to make sure the transformer hasn't shorted internally.I doubt the caps have shorted, and if the diodes all test good in circuit, the next step IMO is to desolder the transformer secondary windings one by one, starting with 9 & 11, then 6 & 8. Or, if you have a DBT or Variac, and a current clamp, you can test for secondary current--there shouldn't be any with everything unplugged. Also, can you tell me where 14/15/16 at the bottom go to? If that unplugs, perhaps try unplugging that first.

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 02:19:32 am
content: I am in the USA, 126ish volts this evening.Interestingly R9 is a jumper on my example. This is odd because the schematic shows R9 as 1M, but the parts list for the A1 board indicates a "wire, tinned copper 22awg." Measuring across the mains input yields 1M which made sense to me when I saw R9 in the schematic but now I am not sure what is going on there.

author: George Edmonds
author_rank: Frequent Contributor
timestamp: October 20, 2020, 02:38:29 am
content: HiMay I suggest that you contact Artek and get a better copy of the manual, they have it for $10. The copy that I have from the keysight web site is almost unreadable, My advice to use a series bulb has not changed as this will prevent damage whist putting full voltage on the components.George G6HIG

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 03:15:52 am
content: Strange, I have a copy from Keysight as well and it is very clear. Perhaps there is more than one available through them?Here are the secondary winding resistance measurements, t3 in situ:6-junction of CR6/CR9- 3.2 ohms7-junction of CR6/CR9- 1.6 ohms6-7- 2 ohms9-11- 8.2 ohms10-9- 4.1 ohms10-11- 4.1 ohms14-16- 1.2 ohms14-15- .5 ohms15-16- .7 ohmsThese seem reasonable no?I am suspect of the voltage selector switch, still puzzling on how to test this and verify it is not shorted. Just need to study it more to understand its connections. .

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 03:38:23 am
content: T3 primary:5-4- 9 ohms or so.I read open between what I interpret as the core/ground of T3 and any of the primary or secondary leads.George- I would like to carry out your test but I am not clear on it. I should insert a 100W or less incandescent across the R9 1M position (jumper in my example), am I to jumper the F2 position or should that be open? I apologize if this should have been obvious.

author: bdunham7
author_rank: Super Contributor
timestamp: October 20, 2020, 03:46:15 am
content: Quote from: valley001 on October 20, 2020, 03:15:52 amWhere do 14/15/16 go to? I can't seem to find where they go anywhere on the diagram. 1.2 ohms seems very low unless it is a very low voltage winding like for a VFD. And this is not a VFD display, is it?As for the voltage selector, test it the way I said to start. Pull F2 and measure across C26.

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 04:12:01 am
content: I actually cant find that either (on the diagram).Found it: 14/15/16 go to a three wire cable that connects from A1J2 toA8J2J10 on the GPIB board, where it is met by diodes for rectification. (top left of figure 6-9A)Across C26 with F2 removed I get 8.7 ohms or so.

author: bdunham7
author_rank: Super Contributor
timestamp: October 20, 2020, 04:26:10 am
content: Quote from: valley001 on October 20, 2020, 04:12:01 amOK, so it is power for the GPIB board and the schematic for A8 seems off--on the diagram I think it would be J10. Just disconnect it for now to eliminate that as an issue.If you have reasonable resistance across C26, then your voltage selector and primaries are likely fine. You could try setting the voltage selectors for 240V, verifying the resistance at C26 goes to about 16 ohms. Then you can try one more fuse at half-voltage and if it doesn't blow, maybe you can find your short with some quick measurements of transformer output.

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 05:32:23 am
content: Hmm..with the selector set for 240v I get 35 ohms across C26. I'm guessing this is not a good sign for the 120v primary winding.EDIT- But then, primary winding 1-3 also measures 8.6ish ohms. I am not sure how the 240v position yields 35 ohms.

author: George Edmonds
author_rank: Frequent Contributor
timestamp: October 20, 2020, 07:07:46 am
content: HiI have now found a better copy of the service manual/schematic, there are multiple versions on the Net. most of which are incomplete.When I get back home later in the day I will respond to you. HP have thought about how to fix this psu and have built in test facilitiesGeorge G6HIG Dover UK

author: HighPrecision
author_rank: Unknown
timestamp: October 20, 2020, 07:51:48 am
content: Quote from: valley001 on October 20, 2020, 05:32:23 amHilooks correct to me, 8.6 Ohm in 120V setting is the result of TWO windings in parallel, each of 17.2 Ohm.Setting to 240V the resistance is double: 17.2 Ohm, windings in series 34.4 Ohm.

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 03:37:14 pm
content: That makes sense, I did not think about 120v windings being in parallel.Am I correct that F2 blowing is related to T3 and then the associated rectifier U1 and filters C20/21? Can CR1-4 and C2-4 be related to this issue?

author: bdunham7
author_rank: Super Contributor
timestamp: October 20, 2020, 03:50:09 pm
content: Quote from: valley001 on October 20, 2020, 03:37:14 pmI didn't follow the primary switching either, although it is pretty standard. How they get 100V is sort of interesting, but also common. Anyway, that looks fine.As far as F2, if the schematic is correct and you have removed the A2 and A4 boards and disconnected the cable to A8-J10, then your problem is confined to the area to the left of connector XA2P1 on the main board--T3, the rectifiers, capacitors, resistors and wiring. Unless I'm wrong or something weird is going on. I would be pulling out the transformer leads in the order I mentioned before, unless that is very difficult. I'm not sure how you tested the rectifiers, but my prime suspect would be U1.

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 03:57:19 pm
content: The trouble is I do not get any dead shorts in U1 measuring it in place. Is this a flawed methodology?T3 is soldered directly to the board, so it is not trivial removing leads from the circuit. Would be easier to remove U1 I think.

author: HighPrecision
author_rank: Unknown
timestamp: October 20, 2020, 04:00:55 pm
content: Quote from: valley001 on October 20, 2020, 03:37:14 pmNo, this part of circuit is protected by fuse F1.QuoteAlso possibly related to diodes from CR6 to CR9, connected to another secondary of T3But I'll try to remove C26 X-rated film capacitor, often these capacitors explode without a dedicated fuse as F2, especially the old RIFA ones

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 04:07:12 pm
content: Quote from: HighPrecision on October 20, 2020, 04:00:55 pmRight, those test fine, CR6-9.C26, is there an accurate way to test this cap or do I simply remove from circuit and test without it in place?

author: HighPrecision
author_rank: Unknown
timestamp: October 20, 2020, 04:13:54 pm
content: Quote from: valley001 on October 20, 2020, 04:07:12 pmTesting the capacitor removed from circuit with high voltage, I suggest to replace this capacitor anyway.

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 04:18:10 pm
content: I have some .047uf film caps ill swap one in and see if that makes a difference.

author: bdunham7
author_rank: Super Contributor
timestamp: October 20, 2020, 04:53:40 pm
content: Quote from: valley001 on October 20, 2020, 03:57:19 pmOK, a many-pinned xformer soldered to the board is no fun, and it probably isn't bad. Do you have any vacuum desoldering equipment? Even a hand-held solder sucker? Looking at the diagram, I'm guessing the easiest path is to remove the rectifiers.As for testing, you want to use the diode check function and test both ways for each diode--you should have 0.6V one way and a completely open circuit the other way.

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 04:57:18 pm
content: Thank you all for your assistance.I will:1) Replace C26. I only have .1uf X cap in my inventory. Will this work in a pinch? I have .047uf film caps but they are not X rated type.2) Remove and check U1 rectifier diodes out of circuit.

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 08:14:06 pm
content: U1 tests fine, I have reinstalled it.I have a substitute in the C26 position, now waiting on fuses to arrive so I can test.The cooling fan is "B1" on the schematic, on the 120v primary. It is also on my suspect list. The resistance of its coil reads 211 ohms, not sure if that is reasonable or not. It does say it should draw between 150-200 milliamps.

author: bdunham7
author_rank: Super Contributor
timestamp: October 20, 2020, 08:25:30 pm
content: Quote from: valley001 on October 20, 2020, 08:14:06 pmI would suggest taking the rectifiers all out (take a photo first) because that isolates the transformer. Then put them in one bank at a time. Even if the rectifiers themselves aren't the problem, you can identify which branch of the circuit is bad.Is the fan a square muffin-style fan and does it say 'impedance protected' on it? 211 ohms seems OK, but can you disconnect it just to be sure?

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 08:57:14 pm
content: It is, and it does say impedance protected.I have tested everything down stream from T3, I lifted legs of C20 and C21 and they test fine. CR6-9 seem OK. That leaves me with C26 and the fan (which will remain disconnected for now).Ill test again when I have fuses. I've made up a dim bulb tester also. If it continues to fail I will remove U1 and CR6-9. That would narrow it down to T3, or the fan.

author: bdunham7
author_rank: Super Contributor
timestamp: October 20, 2020, 09:17:59 pm
content: Quote from: valley001 on October 20, 2020, 08:57:14 pmWhat do the 14/15/16 windings measure disconnected?

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 20, 2020, 09:42:04 pm
content: Hi,For those playing along at home, here is the part of the schematic with T3:You can disconnect the parts that I have circled in Red. The unit will work without the fan or the X cap C26.You can isolate the transformer by removing the full-bridge rectifier U1 and disconnecting one end of the rectifiers CR6-9.If the fuse still blows with only the transformer connected, it is possible the transformer has a defect called a shorted-turn. This means the resistance of the windings will read correctly or close to correctly, but the shorted turn will cause excessive current to flow in the primary, blowing the fuse F2.Regards,Jay_Diddy_B

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 09:49:12 pm
content: Thank you Jay, yes that is what we are looking at.UPDATE-I am happy to report I have a somewhat functional A1 board.With C26 removed it will now power on and remain running without blowing the fuse. This eliminates T3 and associated components and the fan. Ill be putting in a mouser order for a new X cap.Here's hoping the power mesh and computer bits are in working order...

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 20, 2020, 10:20:22 pm
content: Hi,The date code on that Rifa CV6 is June 1987. I don't know if that is consistent with other date codes in your unit?I have been using:B32022A3473M289‎orPHE850ED5470MD13R06L2in this location.You should probably change C20 and C21 while you have the board out.These are 1000uF 50V 105C 7.5mm pitch electrolytic capacitors.Refer to this message:https://www.eevblog.com/forum/testgear/hp6035a-500v-5a-1kw-power-supply-repair/msg697835/#msg697835And bad Rifa caps.https://www.eevblog.com/forum/testgear/hp6035a-500v-5a-1kw-power-supply-repair/msg3281284/#msg3281284Jay_Diddy_B

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 10:45:14 pm
content: I plan to have this in more or less regular use so a recap is in the plans. Once I have it working ill tear it down once again and replace those two. I am afraid to see the price on the 400v caps.Roughly yes, 1986/1987 seems to be the general date range in this thing.Did you replace all the Y caps in yours?Quote from: Jay_Diddy_B on October 20, 2020, 10:20:22 pm

author: valley001
author_rank: Frequent Contributor
timestamp: October 20, 2020, 11:02:04 pm
content: Looks like I am in for some more fun.Installing the GPIB board now causes the bulb on my dim bulb tester to stay lit. Unplugging the power lead from T3 to the GPIB, 14/15/16 on T3 resolves the issue. Going to look at the associated diodes and cap.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 20, 2020, 11:43:49 pm
content: Hi,You can try this:1) with the GPIB board out of the unit, measure the resistance from the 5V. You can measure between pins 8 and 5 on U31 for example. You may have a shorted deoupling capacitor.2) Can you try connecting a bench power supply set to 8V to J10-1 and 0V to pin J10-2and measure the 5V rail.3) The LM309K is a 1A regulator, so I would expect the current to be less than 800mAJay_Diddy_B

author: valley001
author_rank: Frequent Contributor
timestamp: October 21, 2020, 12:06:38 am
content: Actually this example has a different GPIB board.I found C20 to be a dead short. What else should I look at here? Hoping this did not fry the digital stuff down the line.

author: bdunham7
author_rank: Super Contributor
timestamp: October 21, 2020, 12:14:28 am
content: Quote from: valley001 on October 20, 2020, 09:49:12 pmSo your RIFA cap:1) measured OK (not shorted) with a DMM2) conducted enough at 120VAC to blow the fuse but,3) didn't explode all over the place.That's a first, but a good result. Replace every single cap that looks like that whenever you see them. Get a bulk deal on them from Mouser--they have a nice price break at 100.

author: bdunham7
author_rank: Super Contributor
timestamp: October 21, 2020, 12:17:54 am
content: Quote from: valley001 on October 21, 2020, 12:06:38 amA dead short when removed from the circuit? What does it look like?

author: valley001
author_rank: Frequent Contributor
timestamp: October 21, 2020, 12:21:32 am
content: Looks totally fine. Dead short.

author: bdunham7
author_rank: Super Contributor
timestamp: October 21, 2020, 12:29:29 am
content: Quote from: valley001 on October 21, 2020, 12:21:32 amOK. Order up a replacement, no need to be picky--just get the lead spacing and size correct. Meanwhile, for testing purposes, you can bodge almost anything in there. 1000uF + and any voltage over 35 will work. The rest of the board may well be fine.

author: valley001
author_rank: Frequent Contributor
timestamp: October 21, 2020, 01:23:19 am
content: Bodged in a cap (two actually, 680uf 100v in parallel). Making progress!

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 21, 2020, 03:00:40 am
content: Hi,The OT circuit starts with a thermostat on the power board:It should be fairly easy to troubleshoot this circuit.Regards,Jay_Diddy_B

author: valley001
author_rank: Frequent Contributor
timestamp: October 21, 2020, 04:19:32 am
content: That must have been an anomaly, it has not thrown the OT warning since.R20 and 21 on the A1 board get HOT!, 160 deg F or so. Is this normal?

author: George Edmonds
author_rank: Frequent Contributor
timestamp: October 21, 2020, 04:40:51 am
content: HiThey are 5W resistors so they will get hot.George G6HIG

author: valley001
author_rank: Frequent Contributor
timestamp: October 25, 2020, 10:06:55 pm
content: Hi all,Just a quick update.My 6038A seems to be working. C20 on the HPIB board was a dead short and I replaced the X cap on the main board. I also replaced all of the other electrolytics on the daughter boards as well as C20 and 21 on the main board. All of the other caps I removed tested perfectly, I had expected one or two others to be at least marginal but they all showed very good capacity and low ESR. Go figure.I have not run it up to 10 amps yet but I put a lead acid on it limited to 5 amps and it happily obliges (charging a smaller batt in the pic below).Thank you all for your help with this. Cheers everyone.

author: alm
author_rank: Super Contributor
timestamp: October 26, 2020, 06:14:36 pm
content: Congratulations on the repair! Maybe you already know this, but it's recommended to use protection, like a series diode rated for the current, when charging batteries using a bench supply. If the power supply loses power, for example because of a power outage or a breaker tripping, the battery will force power into the power supply, and reverse-bias some junctions.Also, if you'd turn down the voltage with the battery connected, the active downprogrammer, which I believe this power supply have, will try to discharge the battery. The over voltage crowbar may short the battery when tripped. Depending on the size and impedance of the battery, this can produce some fireworks.

author: Jay_Diddy_B
author_rank: Super Contributor
timestamp: October 26, 2020, 10:43:04 pm
content: Hi group,I just finished working on a very similar power supply. I was working on the HP 6033A, this is a 20V 30A 200W unit.These pictures will look very familiar to valley001. You almost have to remove every screw in the unit to get the main board out.andI replaced the Rifa Y capacitors and while I was there I replaced the 1000uF 50V axial electrolytic capacitors.These parts should be common between the 6033A and the 6038A.Parts usedCode:HP 6033A CapacitorsDescriptionQTYMFG Part No.DigikeyCAP FILM 2200PF 20% 1.5KVDC RAD2B32021A3222M289495-5035-1-NDCAP FILM 4700PF 20% 1.5KVDC RAD2PHE850EA4470MA03R17399-5417-NDCAP FILM 10000PF 1.25KVDC RAD2PHE850EB5100MB04R17399-5419-NDCAP FILM 10000PF 20% 1.5KVDC RADor 2B32022A3103M289495-4916-1-NDCAP ALUM 1000UF 20% 63V AXIAL2MAL213818102E34249PHBK-NDRegards,Jay_Diddy_B

author: valley001
author_rank: Frequent Contributor
timestamp: October 26, 2020, 10:59:10 pm
content: I left the original Y caps in mine for now, didn't want to spend the money until I was sure I had a working unit but boy is it a pain to get that main board out! Also, those transformers weigh a ton so some care is needed when handling the PCB to avoid damage from the unsupported weight. Ill probably do the Y caps when I find a suitable quiet replacement for the fan. I also missed an electrolytic cap on the power mesh board.I did NOT know about the use of a diode but that makes sense. Ill scrape through the parts bin and see if I can muster up something appropriate.