SDG1025 overvoltage and relay malfunction repair - Page 1
Forum section: electronics / repair

author: sourcecharge
author_rank: Regular Contributor
timestamp: September 22, 2018, 04:11:04 pm
content: 10/4/18 UPdate: I will be replacing all analog ICs and semiconductors on the front and back of the old and new versions of the MF and I have completed the list for part ordering.Total cost for replacing all parts on the top side listed for 1 FG was about $110.00 including shipping.-------------------------------------------------------------------------------------------------------------------------------Ok, so I OV'd my CH1 of SDG1025 FG.It's 280 dollars to have it repaired at siglent (including shipping), or 319 for a new one.I tracked it down to a bad THS3095 (U19) which was about a 10 dollar part, and a bad 25 ohm resistor (R154) from a secondary opamp CLC1606 (U46). [Side note: the new SDG1025 now use a LMH6702 as U46 and U58 while the rest of the CLC1606 (not available) have been replace as OPA695 (U37,U40,U52,U51,U48, and U38) ]I replaced it, and Ch1 worked perfectly, until I made sure Ch2 worked too as well.Ch2 was outputing lower voltages so I did a self calibration.Then both Ch1 and Ch2 didn't want to work at all.I opened it back up and found a solder ball had somehow got flung between two pins of the opamp 5166iSZ (U59).It was between the 5V and the output of the op amp.I replace U59, and both channels were still not working.After some testing, I found the relays don't work.There are 2x 5V power points on the FG, and they are not connected together.The relays (and other components) operate on one 5V (VCC5V) while all of the analog op amps from Ch1 and Ch2 operate on the other (+5V).The 2 ICs that control the relays are UN2003A (U74 and U71, which are 8 transistor/buffer inverters per package), and those are controlled by 2x 74ahct595 which have the markings on the IC of HB595 (U36 and U39, which are serial to 8 parallel registers with the first register feeding the second with the last inverted parrallel output.) All of these ICs run off of the VCC5V output.Testing the input to the series data input of the first register has found that the signal is high and does not change with a repeatable sequence when the Ch1 or Ch2 output buttons are pushed. (although I can still hear one of the relays switching)The series data input of the first register leads to the fat ribbon wire to the interface panel, and is leading to both Ch push buttons.The other side of the capacitive push buttons leads to the ribbon cable interface of the LCD ribbon where, there is a second pin on the interface that is shorted when ch2 button is pushed. This pin leads back down through the fat ribbon cable back the mother board to the 6 pin IC. When the markings on the IC is read from the orientation of the three pins as being the bottom, the package has the marking of:z16BIt's labeled U60o on the block diagram schematicThe new version is marked:z166I've done searches on these parts, and I can't find any information.If anyone has any ideas or knows what this IC is, or even possible knows what's wrong with this FG, I would be very greatful for your help. I'm in it for the long haul, and I am even looking at replacing the FPGA or the controller if need be but I would like to exhaust all other possiblities first.Here is what I have so far relating to part numbers an their block diagram number that I'm also including.---------------------------SDG1025------------------------DAC904E28 pinU54,U45Marking on part:DAC904E2ACLD9XNEW VERSIONB3GA4.5ZRelay 8pinRAL14,RAL15,RAL16,RAL11,RAL18,RAL9,RAL10,RAL19,RAL20,RAL8,RAL12,RAL21,RAL13Marking on part:B3GA4.5ZOLD VERSIONUD2-4.5NU(not available)Relay 8pinRAL14,RAL15,RAL16,RAL11,RAL18,RAL9,RAL10,RAL19,RAL20,RAL8,RAL12,RAL21,RAL13Marking on part:NEC JAPANUD2-4. 5NU3A1312Fsn74ahct59516 pin (serial to parallel registers that control the transistors that control the relays)U36,U39Marking on part:(TI insignia)HB59534KG4AXGLULN2003A16 pin (transistors that control the relays)U74,U71Marking on part:(TI insignia)UN2003A34AG3P05MNC7WZ166 pin (buffer)SC-70-6U60oMarking on part:z16BNewNC7WZ166 pin (buffer)SC-70-6U60oMarking on part:z166------------------------------Overvoltage and Relay Malfunction IC/Semiconductor Replacement List-------------------------------------OLD versionBAV993pin DIODE ARRAY SOT-23Q3,Q4,QA8,QA9,QA13,QA5,QA10,Q19,Q27Marking on part:A7(sideways)xNEW versionBAV993pin DIODE ARRAY SOT-23QA8,QA9,QA13,QA5,QA10,Q19,Q27,[Q3,Q4,Q6,Q7]on backside of MBMarking on part:A7(sideways)xTHS30958pin OPAMPU19Marking on part:3095TI 18ZCRZ4G3NEW versionOPA6958pinU37,U40,U52,U51,U48,U38Marking on part:TI OPA695695YVNEW versionLMH67028pinU46,U58Marking on part:5A5CLMH6702MA(note: OPA 695 looks like it has better performance than the LMH6702, and it was substituted to save money)OLD VERSIONCLC1606(not available)8pinU46,U58,U37,U40,U52,U51,U48,U38Marking on part:CLC16061239Z15166iSZ8 pinU59Marking on part:5166iSZB149W7(Elantec marking)OLD VERSIONTL072C8 pinU104,U101Marking on part:TL072C32kAT88T4NEW VERSIONTL072C8 pinU104,U101, [U108, U110]on backside of MBMarking on part:TL072C32kAT88T4AQY214S4pin RelayUA50Marking on part:COSMOY214SM27ISL282108 pinU103,U91,U106,U102, U89Marking on part:28210FBZ -CB308FPNEW version8512A8 pinU103,U91,U106,U102, U89Marking on part:(sold box with cut out of right pointing equallateral triangle), (# or $$ symbol)16527910(note: ISL28210 looks like it has better performance than the 8512A, and it was substituted to save money)OLD VERSION74HC405116 pinU47,U42Marking on part:(NXP insignia)74HC4051DL2K3C806UnD1314DNEW VERSION74HC405116 pinU47,U42, on backside of MBMarking on part:(NXP insignia)74HC4051DL2K3C806UnD1314DVCA82214 pinU26,U25Marking on part:(TI insignia)24CSGEKVCA822ID G4ADCMP56220 pinU35Marking on part:2552125.1ADCMP562BRQadc121s1016 pinU61_1Marking on part:X01CSBC846BLT3GSOT-233pinQA4,QA3,QA16Marking on part:1B 4(sideways)4OPA7278 pinU49Marking on part:AUE32C6REF3030SOT-233pinU73Marking on part:R30FDAC858016 pinQ27Marking on part:(TI insignia)D8580109TA97RMMBTH10LT1sot23-3QA2Marking on part:3EM (sideways 4)PMBFJ309sot23-3QA1Marking on part:49W (sideways 29)NEW VERSIONLM33914pinon backside of MB------------------------------------ONLY ON BACK SIDE OF NEW VERSION SDG 1025-----------------------------LM33914pinU27TL072C8pinU108, U11074HC4051D16pinU53BAV993pin DIODE ARRAY SOT-23Q3,Q4,Q6,Q7Marking on part:A7(sideways)xPlease correct me if you think I got one of these wrong to increase knowledge of SDG1000 series repair.Thanks

author: tautech
author_rank: Super Contributor
timestamp: September 23, 2018, 10:22:42 am
content: Sorry I don't have anything useful to help you other than this other recent thread:https://www.eevblog.com/forum/repair/siglent-sdg-1025-schematic-diagram-(or-what-is-the-u63-chip)/Follow the links and you might find some info to help.

author: sourcecharge
author_rank: Regular Contributor
timestamp: September 23, 2018, 11:33:47 am
content: Quote from: tautech on September 23, 2018, 10:22:42 amThanks, and I have read that thread all the way through. It has alot of good info.I think I figured out U60o..It's a dual buffer, most likely this one.NC7WZ16 (package: SC-70-6)I have tested signals from and to the pinouts and it seems to be correct.The inputs of the dual buffers are conneted together and the signal in and out look the same but they do not look like the series input of the register. The inputs of the dual buffer IC is connected to the BIG CHIP IN THE BACK (ADS something or other)...........not good...I remeasured the series register input and I found it was an inverted signal that was giving a repetetive bite. Not sure if that matters but the input to those buffers looks like 2 inductor ringing pulses. I would think that the signal to the bufers from a uC would be level pulses, not rung down logic pulses...I wonder if that chip stores the firmware and if not maybe it can be replaced?IDKMore investigating is required.

author: sourcecharge
author_rank: Regular Contributor
timestamp: October 03, 2018, 02:11:43 am
content: So, I've tested some more and found that TP 15 and 16 are both doing some interesting things like someone may have already figured out what went wrong.https://www.eevblog.com/forum/testgear/the-sdg1000-and-sdg800-thread/msg787268/#msg787268Although I do not have exactly the same problem, and with the relays too cycling, I've decided to simply replace ALL of the analog and digital ICs that are connected to the +5V output.I have updated the list above for most of the ICs including the small sot23 ics, and the only ICs on the analog side that I do not plan on changing are the 2 big DACs because they seem to be doing their job and they are not connected to the analogs +5V output.The only ICs that I still need to find are:QA1UNKNOWNsot23-3Marking on part:49W (sideways 29)After this one ICs is identified, I can order all of the parts and start replacing all of the ICs on this FG.Anyone have any Ideas on these parts? I've done extensive searches already. I've come here because I have run out of ideas.Thanks for any help you can give.EDIT:AUE 32c6 = opa727parts list updated

author: sourcecharge
author_rank: Regular Contributor
timestamp: October 03, 2018, 03:42:00 pm
content: So, I just figured out what AUE 32c6 was, as it was the TI OPA727 op amp.The very last unidentified IC or semiconductor left on the (top) analog side for the SDG1025 is labeled:49W(with a sidways)29I'm thinking its a transistor, but I can't find it listed under any smd code listings.Anyone?Here is a picture of the part:https://sigrok.org/wiki/File:Siglent_sdg1010_analog_cosmo_y214s.jpg

author: sourcecharge
author_rank: Regular Contributor
timestamp: October 04, 2018, 04:16:23 am
content: Quote from: sourcecharge on October 03, 2018, 03:42:00 pmI found it!it's:PMBFJ309Updating parts list aboveNow I am going to replace all the analog ICs for this and hope that it works.I have found that the relays click twice when turned on on the old version, but the new version only clicks once. I'm not sure if this is a problem with the digital side, but I'm hoping that it will either solve itself when all of these chips get changed, or it doesn't really matter, but for what I have found is that the new version and the old version serial data in and clocks to the ICs that control the relays are very close. So, I'm thinking that there might be a different reason why the relays are cycling other than the digial input and the control ICs of the relays. Maybe the self calibration caused it, and when the ICs are changed, the self calibration will solve it. IDK...Wish me luck

author: sourcecharge
author_rank: Regular Contributor
timestamp: October 04, 2018, 04:25:31 pm
content: So I just took the MB out of the new version SDG1025, (did I mention that I OV'd it too about a month ago?) and I was going to start taking off all of the ICs that I intended to replace on both MBs.On the back of the new version of the SDG1025, I found 4 extra ICs and some of the sot23 A7 doides were put on this side instead.I'm going to update the parts list and since it's actually a new pcb layout, I have not taken a picture of it yet but I will soon.

author: tautech
author_rank: Super Contributor
timestamp: October 04, 2018, 04:54:44 pm
content: Other than the last 4 digits in the SN# there's indication of the build date and HW revision so it might be useful to show those #'s with respect to the PCB picture.In early products the build date was easy to determine but not so much now as the SN# contains mostly lettering except the last 4 digits, the SN# of that HW version.

author: sourcecharge
author_rank: Regular Contributor
timestamp: October 04, 2018, 05:04:37 pm
content: Quote from: tautech on October 04, 2018, 04:54:44 pmIt might be easier just to explain how the SN# are used to date the production with this unit for the old and new versions instead?I could look and just post the production dates?

author: tautech
author_rank: Super Contributor
timestamp: October 04, 2018, 06:02:20 pm
content: Quote from: sourcecharge on October 04, 2018, 05:04:37 pmLike I said, it's not so easy now.As some example here's the SN# from a recent production DSO built a couple of months ago: SDS1ECDQ2R****.SDS1E is the model, it seems CD is the HW version and Q2 indicates 2nd quarter production but your guess would be as good as mine. Is R production year, maybe.As a comparison, a SDS1kCML scope sold late in 2015: SDS100P215****, production 2nd quarter 2015.So yes the product SN# coding has changed some.

author: sourcecharge
author_rank: Regular Contributor
timestamp: October 04, 2018, 08:03:34 pm
content: Using your logic on the older one I got, its 3rd quarter 2013.The newer one has "Q1R" as the date code...so good luck on that, but I bought it this year.

author: sourcecharge
author_rank: Regular Contributor
timestamp: October 15, 2018, 03:19:12 am
content: Well, I got done replacing all of those chips.Both FG are now working 100%I am very happy with the results.Due to the lack of interest, I'm not going to bother uploading the pics of the bottom of the new version mother board.Now I've got alot of soic op amps that I need to test so that I can use them in making other things.

author: TheSteve
author_rank: Unknown
timestamp: October 15, 2018, 03:35:17 am
content: Congrats on the repair!I'm sure down the road others will benefit from you sharing the repair and the part numbers.

author: sourcecharge
author_rank: Regular Contributor
timestamp: October 15, 2018, 05:22:34 am
content: Thanks, and I do come here often so if anyone has questions about my repair, I have pics butno interest here I guess.

author: tautech
author_rank: Super Contributor
timestamp: October 15, 2018, 06:43:51 am
content: Quote from: sourcecharge on October 15, 2018, 05:22:34 amJust as TheSteve has said, others will benefit from this thread and any info, pics included that you can share with us.Your repair would have been much easier if you started with the info you have learnt.Please share.TIA.