Circuit Board Numbering

[Root Boy]

Does anyone know what the letter on a circuit board after the number means? i.e. Can I replace a IF-7758B with a IF-7758C ? Also, does Furuno test/repair boards this old. (early '90's) -Thanks.

 

[Johnny Electron]

The IF-778B was the IF amp board used in the older 1930/1940/7040 radars.
The IF-7758C was used in the 1750/1731/1750 radars
The first is logarithmic and the other is linear so there is no compatibility.

 

[Root Boy]

Thanks Johnny E. Yes, this is a Model 1940. How about sending boards or the whole chassis in for repair? I was not getting any return, so tested the Magnetron per the manual and it was no good. Also this failure was Magnetron-ish. Returns got worse and worse over a few days until nothing. Replaced that and now voltage tests good, but still no return signals. Actually just a little bit The biggest metal rooftops here at the marina/park are all I can get as relatively small blips. Manual tuning does nothing. Between coarse and fine I am getting the full 5-35VDC to the scanner, but no change at all on the display. Troubleshooting from the manual leads to the IF and MD boards, but I can't seem to find exact matches out there. I know it's old, but was a good radar and to me it's worth putting a few hundred bucks into...

 

[Johnny Electron]

Yes the service center can still evaluate these for repair. No need to send the cables as they have that. $140 evaluation fee if you don't repair and have been given a repair option, plus return shipping. RMA and shipping information can be obtained via our website (www.FurunoUSA.com - Support - RMA)