Please help me identify U1. Cry for HELP. Please save my steering wheel.   - Page 1
Forum section: electronics / repair

author: Valentin Danev
author_rank: Newbie
timestamp: October 01, 2020, 04:38:56 pm
content: Hi All,Please help me identify U1.I thank you in advance for attempting to help me.I have a Logitech G27 steering wheel for my PC.Unfortunately recently it stopped working. Looking it to the problem it looks like one of the chips must have got knocked off or fell off.I am struggling to identify what the chip is in order the replace it. I have managed to find a picture of the thing but I have no idea what it is.The board is behind the motor with IR and encoder wheel. I hope somebody can recognise it (please see the picture Element U1) and save my wheel from a dumpster dive.Thank you in advance.Valentin Danev

author: NivagSwerdna
author_rank: Super Contributor
timestamp: October 01, 2020, 04:59:26 pm
content: Are you sure?I did a google and found an ebay replacement board which had the opto parts and no IC

author: james_s
author_rank: Super Contributor
timestamp: October 01, 2020, 05:44:35 pm
content: Nothing was ever installed in that spot, you can tell by the round solder balls, if a part had been in that spot there would be squared edges. It is very common to have un-populated spots on boards.

author: thinkfat
author_rank: Unknown
timestamp: October 01, 2020, 08:49:25 pm
content: I'd call that a "jigsaw accident".

author: james_s
author_rank: Super Contributor
timestamp: October 01, 2020, 08:56:17 pm
content: Looking at that again, was there a trace along the left edge of that slot? What happened to that thing? Did the encoder wheel come loose and rub away the edge of the PCB?

author: Valentin Danev
author_rank: Newbie
timestamp: October 01, 2020, 10:56:55 pm
content: The picture is not of my board. I am trying to identify U1 not C1.

author: fzabkar
author_rank: Super Contributor
timestamp: October 02, 2020, 01:59:01 am
content: 74LVC2G17GW, Philips, dual non-inverting Schmitt-trigger with 5V tolerant input, 1.65V - 5.5V, marking VV, SOT363:https://assets.nexperia.com/documents/data-sheet/74LVC2G17.pdfpdf.datasheetcatalog.com/datasheet/philips/74LVC2G17GM.pdfOn your board, and the one in the Google search, are there links between pins 1 & 6, and 3 & 4, perhaps on the underside of the PCB? AISI, the Schmitt trigger would only be necessary if no such function were incorporated in the opto parts themselves.

author: Valentin Danev
author_rank: Newbie
timestamp: October 02, 2020, 09:06:31 am
content: Thank you so much

author: rvalente
author_rank: Frequent Contributor
timestamp: October 02, 2020, 12:03:35 pm
content: Hahah this was one the funniest topics ever, "CRY FOR HELP" gotta fix my logitech steering wheel.By the topic call I imagined you've damaged a 80K equipment or something and you job was at risk.

author: Valentin Danev
author_rank: Newbie
timestamp: October 02, 2020, 01:15:33 pm
content: No, it is even worst than that.No wheel no drift.No drift no life.You lads just saved my life as I was feeling suicidal.Wheel=Drift>Life

author: fzabkar
author_rank: Super Contributor
timestamp: October 02, 2020, 06:00:29 pm
content: @Valentin, I'm not sure that you understand my comments. I don't believe that U1 is always installed. On those occasions where it is not present, there would be two links between the two sets of input and output pins. If these links are present on the underside of the PCB, then you have a different problem, most likely in the opto parts.I would slip a card between the opto parts and measure the voltages at pins 4 and 6 of U1.

author: m3vuv
author_rank: Super Contributor
timestamp: October 02, 2020, 06:40:31 pm
content: sounds like you need to get out more often!!

author: TheSteve
author_rank: Unknown
timestamp: October 02, 2020, 07:47:54 pm
content: Must have been some pretty involved drifting to rip parts off your PCB.

author: Valentin Danev
author_rank: Newbie
timestamp: October 03, 2020, 09:45:41 am
content: I do understand your comment.Thank you for your help. I think in this version of the board is always installed.