CF7000 coin changer control board

[brauliochi]

Hi, my name is Braulio, I repair http://www.meigroup.com/australia_nz/vending/vending_products/coin_mechs/mei-cashflow-cf7000/, and have a questions, they control board sometimes burn's, and discover that quit the flash chip fixit, dont burn a transistor pnp protection, my questions is... if I change the flash chip from another control board, they should works? they have a id protections?
the MCU is M308B8SGP
the flash chip is M29W800DT
the RAM is CY62146EV30
MEI's dont provide the squematics
I read succesfull a flash chip with a TNM5000 programmer, but i dont sure if a buy a new one flash chip and flashed, will work with this, i never work with a renesas mcu

[thm_w]

This is just a guess, but I doubt they would secure it in that way. M308B8SGP has no storage memory, must run off the flash only. A new flash chip is $1, so it seems worth the time.
I don't have a flash programmer.

Whats the pnp protection? Does it seem like the MCU and RAM is not damaged by whatever burned the flash?

[brauliochi]

Hi thm_w sorry for my late reply, I was sick with hepatitis A, apparently very commun in my third world country  , I was out 1 month, but now i fine, the pnp protection is a transistor located in the second power supply (3.3V output) of the board, if there is a short circuit in the IC's powered with 3.3V, this transistor blowout, working like fuse, if i desolder the flash, and change the transistor, turn on ok, the short circuit is gone, but now dont do it anything obviously, I already change the flash and turn on all ok, but a error a new error appear, "error in sensor coin"
I think that need a new calibration with the software, but dont communicated with the computer!! now i'm stuck, I share a squematic that i try to do, only following traces and searching google ic's marks
you need install circuit maker
http://circuitmaker.com/Projects/ProjectAccessDenied/braulio-chi/Control-Board-CF-7000
send me a request permission

[thm_w]

Heres a larger photo if anyone is curious about the parts. Since sticker is on the flash they probably pre-program it at an earlier stage.
Will send board soon.

[brauliochi]

Thanks for the photo, much much better, I do not know that it can be causing the flash to burn, since the other components have no fault, it is often only the flash

[stj]

how are you programming these, do you have a CPM module?

[brauliochi]

Yes, but i prefer use the cashflow STS software and the cable serial, I succesfull change the flash chip, and turn on the coin changer, but now, a error appear, coin sensor error, i change the discriminator, thinking that maybe is the coil sensors, but no, still the same error, then I try to connected to the PC and software and dont communicated, I look at the signal tx with an oscilloscope, to know if the signal reaches the pin of the microcontroller, and if it arrives, so dont know is a problem of baudrates. Dont know how measure the baudrate with oscilloscopes, so I will solder a tiny cables to my logic analyzer

[stj]

maybe you have another issue, that type of error is usually an optical sensor.

if you have a CPM, do you have the WSM pc software to load it up?

[brauliochi]

Yes I have the software the cashflow sts, I recently talk with a engineer from MEI, and told me, that when that error appear, is useless try to repair, and this error occours when have a variation of voltage, damage the flash and sometimes the MCU, and a new version of the control board is comming fix that error, so, no much to do, only in some ocassions fixed when I change the flash, I think its maybe a checksum protection avoid reverse engineer, If you want the .bin image, send me your email, best regards

[CzokNorris]

Hey, does anyone here know if there is an easy way to find a serial interface on those devices?
I want to integrate a CF7000 into an environment which doesnt use MDB, but instead just simple serial.
Need to send commands to it like "pay out ammount x". And receive commands like "someone added a coin of denomination x" in the most simple way concievable.

[stj]

they have a ttl serial interface called HI² and newer ones may have a second ttl interface that would be better for you called CCTALK.