my mts wont shut off.. um.. help?

[nh7cy]

hello,

i have an mts2000 model III that had a bad display. a little while ago i decided to switch the ribbon cables behind the display and so it turns out i had accidentally shorted out some of the connections. the result was that my radio still worked, it just wouldnt turn off. meaning, the radio would power up, and tx/rx perfectly, but when you turned the volume switch to the off position , the radio would simply stay on, the only difference while in the off position being that all of the buttons would no longer be functional.

i ended up opening the radio and taking a look at the controller board, and it seems that i have found the problem.

the problem seems to be isolated within an 8pin chip on the back of the board labelled "9400" it will either say L34C or T346 from what i've seen.

does anybody know what this chip does or is? i have quite a few that i could pull off of donor radios in order to save my mts but i dont know if they have anything pertaining to the flash or not and i dont want to toolproof my radio.

any help would be greatly appreciated.

thanks!

[nh7cy]

here are a few pictures that might be able to help.







i did a search on the chip directory and it looks like it may be a vco of some sort but im not sure..

[radio-link]

hello,

does anybody know what this chip does or is? i have quite a few that i could pull off of donor radios in order to save my mts but i dont know if they have anything pertaining to the flash or not and i dont want to toolproof my radio.

any help would be greatly appreciated.

thanks!

This is probably a MOSFET (or maybe a voltage regulator, but I do not think so), being responsible for shutting of the power supply. It has died and gives a short circuit between source and drain, so the controller and most part of the RF board keeps turned on, even if the switch says "turn yourself off" :-)

These MOSFETS often can be recycled from olt LiIo batteries, notebooks and other devices with a softbutton for power on/power off. Or you just take it off an old MTS...

[nh7cy]

awesome. thats what i figured, but i just wanted to be sure because i dont want to toolproof my radio.

i have a bunch of mtx controllers lying around that i might just tear that part off of so it should all be good.

thanks!