Ibanez Roadster RS924 - Active EQ Problem

[TheRealStig]

Hi, First post so please be gentle with me.

Recently my RS924 stopped working in active mode, so I gave it a full rewire.  Still does not work in active mode.  I have checked out the battery (new), wiring connections and switches with a meter, all connected but still cuts out in active.

All wires on the active system connect properly and there is continuity through to the traces on the circuit board.

I considered making a new active tone board but I am unable to identify one of the components on the original, and can not find a circuit diagram for it.  The board is marked MP-EGF02.

Can anyone help? 

Pics show - Circuit diagram I used for rewire. Both sides of active tone circuit board.  The component I can't identify is the small glass item on the left of the nearest (bottom) capacitor in the top view.

[atsampson]

That's a diode - something like a 1N4148. It's feeding the op-amp's Vcc pin, presumably so that connecting the battery the wrong way round won't damage the op-amp. In that application any little silicon diode will do fine.

Edit: Have you tried reflowing the solder joints on the board? Some of them look dodgy...

Edited April 24, 2020 by atsampson
Add a suggestion

[fleabag]

What ATsampson said

Just looked at the soldering in detail and its  very messy in places

[TheRealStig]

Thanks, will try the solder joints before I start building circuits.

 

Any ideas for alternative op-amp chips for this kind of circuit?

 

[itu]

4558 is a low quality dual. Try TL072, NE5532... there are lots of alternatives. But, as there are sounds and options, there are also few things to look at: power consumption. 5532 sounds so good, and you can hear it from the battery, too. 072 is a good one and consumes less. OP-series is high end, but so is the price. I still recommend you to try, as the cost is very reasonable.

[LeftyJ]

What finish is that? Was it refinished? I've never seen an RS924 in anything other than black, brown sunburst or transparent violin.

[Tronographic]

I have an extra EQ board if you need it... 

 

Also, they offered that color in the 1982 catalog on the new Medium Scale Roadsters... but I'm never seen it on the RS924... can we see a full picture?

 

https://www.ibanez.com/usa/support/catalogs/19820101000012.html

Cheers,
David

[DirkB]

On 14/07/2020 at 23:33, Tronographic said:

I have an extra EQ board if you need it... 

 

Also, they offered that color in the 1982 catalog on the new Medium Scale Roadsters... but I'm never seen it on the RS924... can we see a full picture?

 

https://www.ibanez.com/usa/support/catalogs/19820101000012.html

Cheers,
David

Hello David,

 

Just got hold of an Ibanez Roadster RS940 ...without the EQ board (MP-EGF02).  Do you still happen to have a spare available ?  

 

Best Regards,

Dirk

 

[TheGreek]

He hasn't been here since 19 July last year.....

[DirkB]

Ok, thanks.  Could not find a replacement MP-EFG02 board at all and decided to hand build a copy of the one I found in an RS924.  Meanwhile completed and  installed in the RS940.  See picture of my MP-EFG02 attached.

[RandomDan]

Hi All, apologies for the thread revival but I found this thread  this week while repairing my RS924 which had developed some circuit issues...

As I'd traced out the PCB I thought I'd share the circuit and my notes in the hope that it might help anyone looking to rewire, repair or restore the same model - I've had mine since around 2000 and It's got a lovely sound, but sometimes a little TLC is needed

 

 

Edited February 15, 2023 by RandomDan
Add battery + diode