Heed help identifying IC - Page 1
Forum section: electronics / repair

author: Pete66
author_rank: Regular Contributor
timestamp: February 24, 2020, 06:08:17 am
content: HelloCan anyone can identify this component? It is in a BOSS SL-20 pedal near the input. It just says 9R 8Z on it. Also there is a small dot above the R and the ZThx

author: forrestc
author_rank: Unknown
timestamp: February 24, 2020, 06:20:17 am
content: Quote from: Pete66 on February 24, 2020, 06:08:17 amIt will probably be easier to recognize if you figure out it's function. Based on the placement, and that it looks like a SOT-223 and that there's a cap near both sides of it, a wild guess is some sort of regulator, probably a LDO.If it's a LDO, you should measure a certain voltage on the input cap, and a smaller voltage on the output. IF the output isn't working, then you can often just pick a correcly voltaged LDO without trying to match the exact part.

author: digsys
author_rank: Unknown
timestamp: February 24, 2020, 06:37:14 am
content: Transistor? Regulator? We need the PCB marking label at least

author: forrestc
author_rank: Unknown
timestamp: February 24, 2020, 07:58:03 am
content: Quote from: digsys on February 24, 2020, 06:37:14 amI think it's labeled as an IC, see the second picture, on the right side it has 'C157', 'IC14', 'C158' with the arrow pointing at the location, so I think that's labeling a capacitor, integrated circuit, capacitor.I'm pretty comfortable that this is most likely a voltage regulator, absent any additional information.

author: rfeecs
author_rank: Frequent Contributor
timestamp: February 24, 2020, 05:37:18 pm
content: Could be a 3.3V LDO:http://www.eric1688.com/product.aspx?id=384478

author: Pete66
author_rank: Regular Contributor
timestamp: February 24, 2020, 07:38:45 pm
content: Thanks I think it is a regulator.But I am getting 1.5V at input and 1.1 at output. So looks like there is something wrong with input voltage. Ill have to trace it I have no schematics. The same input is also connected to all the JRC4558 opamps so I think that would be too low a voltage for the opamps also.EDIT:Turned out to be 3.3V LDO. There was an open Transistor that was going to the input of this regulator. That's why the input was reading 1.5V.I changed it and the IC now has 6V input and 3.3V out. Everything is working. It was an SC-70 package 2SC4116 transistor that was open. In my experience these surface mount transistors fail open instead of short like the through hole ones.Thanks

author: meauummels
author_rank: Newbie
timestamp: February 25, 2020, 06:21:30 pm
content: Sorry ik can't help u , but im im searching for a component 2 from androidbox ik think ist a voltage regulatori hope anyone knows

author: forrestc
author_rank: Unknown
timestamp: February 26, 2020, 01:01:26 am
content: Quote from: meauummels on February 25, 2020, 06:21:30 pmYou'll need to post more information. This doesn't look like a voltage regulator. I'd guess an opamp except that it appears that the right hand side two pins are likely tied to vcc/ground, and that isn't a common pinout for a 5 pin opamp.Do you know what this part of the board is likely doing?

author: wraper
author_rank: Unknown
timestamp: February 26, 2020, 01:27:53 am
content: Dunno if you have realized that but there is corrosion on PCB, including on pads of this component. Seems like liquid damage. And corrosion easily causes current leakage or even short circuit.

author: forrestc
author_rank: Unknown
timestamp: February 27, 2020, 04:56:48 am
content: Quote from: wraper on February 26, 2020, 01:27:53 amI'm assuming you're talking about the second poster's pictures.I don't definitively see corrosion, other than perhaps on the caps near the top (hard to tell, but I agree it does look somewhat corroded/tarnished). I also see what looks like an ENIG board where the solder didn't completely cover the ENIG pads. But the picture is bad enough that I can't tell for sure.