Archive of the former Yahoo!Groups mailing list: Vintage Simmons Drums (UK) Users Group

I powered up my Trixer a few days ago, and one of the LED strips (2nd row, 1-8) had stopped working. Other than that everything else seemed to work fine. Now with it being all 8 out, that kind of shouts out "driver chip faulty..."

Not having the schematics for the Trixer, it was off with the cover and start tracing out how the LED's were driven. There are 3 74HCT574's (IC16-18) which drive all the LED's. Tracing back from the LED's that weren't working led to IC17, and using a logic probe I found that all the outputs were permanently held at high impedance (even though /OE was enabled). Replaced IC17 with one from ebay for a couple of £ and it's now working perfectly.

I wish all repairs were this easy :)