Meridian 207 CD/Preamp

[405man]

I have aquired a faulty Meridian 207 CD/Preamp. Would anyone have any service information for this machine

Stuart

[X.G.]

HI,all

I am repairing a Meridian 207 of my friend which remote device is lost.It can not power on and not display,just light a LED.

I don't have it's service manual too.

I have checked the signal of pressing key is totally correct.I suspect the MCU which is Z0869112PSC is fault.

cause the mark of this IC is ' Z0869112PSC Z8 romless'
,I think I can change it for a new one (in order to check/repair). am I wrong?

Thanks

X.G.

[405man]

I contacted Meridian who emailed me some information. If I can have your address I shall forward it to you

Stuart

[guido]

I have a preamp from that series, think a 206. What i know from the remote: it's on one of the two test adresses that philips has defined in RC5. Cant remember which one. Command codes are standard RC5.

[X.G.]

thanks,405man & guido

my email adress is JMXG007@tom.com

after trace the circuit,I see the CD/pre:
it have 2 MCUs.the main MCU is Z0869112 for system/pre control.the other MCU is MAB8441 for the transport/CD control.the Z0869112 work with the 2764 ROM,so I guess it must be older ROMless MCU like the Z86C91 series now which produed by Zilog.

I have changed the SAA3006 keyboard RC5 encode chip for a new one before I got the idea for check,but the 207 still not work.because the Z0869112 is hard to buy for me,I have changed the 74LS374 and CD4013 which work for Z0869112 as well,the 207 still not work

once when I check the XO circuit of the Z0869112,the CD tray can open...so,I confirm the CD/transport control system should be fine.

basing on the Z86C91 pin diagram,I check the reset pin voltage of Z0869112,and find that is 3V(not high,not low...),not correct!...after I desolder the extend component,it is 3V also.

I know the key of check MCU/PCU include 3 points:1,clock.2,reset.3. communication

after I check the Z0869112 in my ability,Now I mainly suspect the Z0869112 is fault...

I have asked my friend for find the Z0869112....

EDIT: yesterday,my friend told me that the 207 don't work after the holder open it and try to modify....

[guido]

It actually was a 201, cant remember about the controller they used there.

Get hold of a scope and check the clock of the processor, see if the data/adress lines towards the rom are doing anything and check if the rc5 out of the saa works and gets to the processor.

I've opened mine a few times and it still works

[X.G.]

Originally posted by guido
Get hold of a scope and check the clock of the processor, see if the data/adress lines towards the rom are doing anything and check if the rc5 out of the saa works and gets to the processor.

I had check the clock and the 'communication' of Z0869112,the clock is fine,but the data/adress lines towards the rom do nothing

so...I decide to wait the new Z0869112 for repair.

thanks,guido

X.G.

[j_n0s]

Hi

Could anyone help me with any service information for this machine, please?
I didn't have even the cable, that connect two units
Any suggestions?

Thank you in advance!