MCS2000 FL01/90 problem

[MPDREO]

I have a MCS2000 model I UHF mounted in an unmarked Taurus configured with a remote head. On power-up it sometimes displays FL01/90, sometimes it boots up normal. Also, it sometimes powers up with the FL 01/90 and then a few minutes later it will come to life on its own while driving down the road. This has been an ongoing problem for quite some time but the car was assigned to admin so it wasn't a big deal. Now it is used by detectives and I need to address it. Yesterday I swapped out the radio chassis and it powered up ok. I will have to wait to see if this was the problem.

Is there anything else I should check or any tests I can perform to determine if the problem was the chassis, or if it may be the control head or the cable between the two? Being an intermittent problem does that indicate any certain trouble?

Thanks in advance!!!

[wavetar]

Fail 01/90 means that the control head is getting power, but it cannot communicate with the main radio chassis. This error is rarely seen in dash-mount units. In a remote install, 9 times out of 10 it's the interconnect cable, although it could also be an intermittant power connection to the radio chassis. Far less often, it could be an actual hardware issue in the chassis or head, but unlikely.

[WB6NVH]

01/90 is my favorite failure code, because several times I have bought radio drawers quite cheaply, without heads or cables, tagged "Fail 01/90." There has never been anything wrong with the radios, most likely it was a bad power connection on the power cable or something wrong with the control cable. Either way I was happy...

[d119]

I'd be willing to bet some money that the problem lies in the surface mount pin header on either the radio side or the control head side.

I've seen this before on many occasions.

Disassemble the radio and control head to board-level. You'll notice the header that contains the pins that connect to the control cable are surface mounted to the PC board. If you flex the header *GENTLY*, you may find that the solder connections from the header to the PC board have broken loose.

Reflow the solder around each surface mount leg of the header to the board. Then reassemble and test. If this was indeed your problem, it'll be solved.

Again, I recommend checking this on both the radio and control head, though I've only ever really seen it on the radio end, it's worth checking both sides.

PLEASE let us know how you make out, I'm curious to see if this was your problem.