Assembling 3.5 EGT

[lezsi]

Hi!

I've assembled a 3.5 board, so far so good, but have difficulties with EGT which shows 307/308C constantly (in megatune/vemstune) no matter what I'm doing.

First channel parts, solderblob were populated on the PCB already, second is empty.
I only soldered the sensor wire and filter cap.

Input voltage and AD597 output voltage seems OK, even MCP3208 input seems fine (0.1V at room temp), still I get constant 307C for both EGT channels.

Tried with different 1.1.x firmwares too.

Any ideas? 

[GintsK]

I suggest check other MCP3208 inputs - output. Easiest  on inputs 6 and 7 by configuring these for launch.

[lezsi]

I suggest check other MCP3208 inputs - output. Easiest  on inputs 6 and 7 by configuring these for launch.

Input 7 is also dead (configured for ALS), another board is fine in same wiring+fw+conf.  

[GintsK]

I guess you have to change MCP3208. You can get one from webshop.

Gints

[rob@vems.co.uk]

I've seen these die when the chip has been used as a grounding path, the thermocouple is providing a route to ground that needs to be provided by ground straps.

[lezsi]

Yes, I guess I need to replace MCP3208 as 5V supply voltages, GND and data connections around all seems fine.

This is a board on desk without real loads (but all grounds connected) so I hope it's not killed that way.