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Old 01-21-2013, 12:20 PM
stuartjohn24 stuartjohn24 is offline
Officially Welcomed to the 'Fest
Location: Chippenham, Wiltshire, UK
Join Date: May 2011
Posts: 828
Mein Auto: BMW F01
For those of you following...

I have been playing around with this again today, to cut a long story short the amplifier card power supply circuit works ok now after the regulator repair.

However the processor card has still been resetting, I have been playing around checking address lines and data lines on the processor marked '1' in my previous post and suddenly the card started working again.

Probing the board with the scope in the area of the RAM IC (5 in the picture above) seems to fix it, it looks like a dry solder joint fixed by slight pressure of the probe on the board or the added capacitive influence of the scope probe wiring on one of the address lines stabilises it.

The amp stayed powered up for at least two minutes with a torch aimed at the fibre connector!

The picture below shows the processor (2 in the photo) kicking the watchdog IC (11 in the photo) every 976.8 micro seconds, that's basically 1000 times a second! The watchdog will wait a maximum of 1.2 seconds before resetting the processors if no pulse is received from the processor.

I will investigate what exactly is causing the board to 'fix' itself, I'm hoping its a dry joint or corrosion under the RAM IC that I can clean and touch up with a soldering iron.

Anyway will have another look tomorrow, I hope to report some good news and get some bass back in the 7 pretty soon!

2008 F01 - Sophistograu with Saddle Brown Leather
Night Vision, Digital TV, Heated M-Sport Steering Wheel + Paddles, Combox, 6NF Baseplate, 6NR Apps, Rear Entertainment System, Automatic Boot Close and Surround View Cameras.
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