Help identify baked 8msop IC W1465H - Page 1
Forum section: electronics / repair

author: Samogon
author_rank: Frequent Contributor
timestamp: June 04, 2017, 04:44:27 am
content: It hasW1465Hmarkings on the case.It is installed on optical main dial of ICOM IC-746PRO transceiver and i know it has to be comparator IC. but i cant find its datasheet to find proper equivalent.Usually there is used LM393 but it is exists only in 8soic case and won't fit on place of tiny 8msop case.Thank you

author: Armadillo
author_rank: Super Contributor
timestamp: June 04, 2017, 08:45:37 am
content: Could this be the LM293ADGKR.?

author: coromonadalix
author_rank: Super Contributor
timestamp: June 04, 2017, 01:56:41 pm
content: the Icom 746 and Icom 7400 icom 7700 seems to share the same front parts, the services manuals are available on Google, but the schematics of the dial is not shown, just an picture of it in the front panel parts ...the dial is : Sensor Unit PCB EX-2500#01 part number 0880000950 an very hard to find in used parts, try contacting Icom ??There has been some debate on ham forums about similar problems ...http://www.seed-solutions.com/gregordy/Amateur%20Radio/Experimentation/IC756%20Encoder.htmI think your chip is an lm393 not a 293

author: coromonadalix
author_rank: Super Contributor
timestamp: June 04, 2017, 02:03:04 pm
content: the part in service manual is now wrong, the correct one is 6910011090 Sensor EX-2500 #01. It cost $94 plus taxApparently it is an obsolete partthere's some people who managed to get this part working but the shaft is shorter ??http://www.inter-elink.com/Pic/File/RMS20.PDFP/N in the ICOM 746 is Copal RMS20-250-201-1Pgood luck

author: Armadillo
author_rank: Super Contributor
timestamp: June 04, 2017, 03:35:21 pm
content: Have you already probed the hall? Did it survive the static?

author: Samogon
author_rank: Frequent Contributor
timestamp: June 04, 2017, 05:53:06 pm
content: There is optical sensor and it appears to be fine.

author: Samogon
author_rank: Frequent Contributor
timestamp: June 05, 2017, 10:08:24 am
content: Thanks guys, looking onto different datasheets i found that vssop and msop has same size cases.Assuming that most analouge comparators in most cases are pretty generic, i have orderedhttps://www.digikey.com/product-detail/en/BU7232FVM-TR/BU7232FVMCT-NDlow voltage comparator.Will update once installed

author: Armadillo
author_rank: Super Contributor
timestamp: June 05, 2017, 05:57:52 pm
content: Quote from: Samogon on June 05, 2017, 10:08:24 amThe attachment from Element14 is 59cents Singapore, similar device, and you need to buy it at US$1.82 each. LOLOk, I think you have an account with digikey.Good Luck with the repair.

author: Samogon
author_rank: Frequent Contributor
timestamp: June 05, 2017, 06:17:44 pm
content: Yeah on my scale (few items) it does not matter. If this $5 will restore my rig i would consider price difference negligible.And you are right i tend to stick with one provider. I just trying to combine orders to save on shipment.

author: Samogon
author_rank: Frequent Contributor
timestamp: June 07, 2017, 09:58:02 pm
content: he he heI have installed new comparator and found that optical interrupter CPI-250 has open diodeI can confirm that comparator works touching pcb gives me frequency change, but instead of nice square form it has some 1% duty cycle signal on output.Now i only found it sensor on aliexpress and ordered it.While it will fly from distant galaxy i will try find substitutes on major parts suppliers.I should have more than digikey account.

author: Samogon
author_rank: Frequent Contributor
timestamp: July 26, 2017, 07:57:42 pm
content: CPI-250 came to me and was replaced and i can see that it makes its output transistors to close when LED is shaded, good sign.But now i found that schematic for comparator inputs does not correspond usual inputs/outputs layout for lm393 or other industry standard dual channel comparators.I will draw small diagram to show it and figure out how to squeeze ml393 into it.