Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems G68 Failed power supply ?

For those feeling like doing some DIY work on their out-of warranty G68, here is an illustrated step-by-step instruction on how to exchange the original UMEC PSU with a XP Power replacement. This is of course at your own risks. For those who�d rather play it safe, you can always contact Marc Koval in the US, who still perform those PSU replacements.

Order the replacement PSU: XP Power ECM40UT31

01. Make yourself comfortable. I would recommend that people earth themselves to the chassis of the unit using an electrostatic wrist-band to prevent electrostatic damage to components. Obviously the unit should not be connected to the mains supply while working on it.

02. Remove the (4) top anodized aluminum cover bolts with a 3mm hex screw

03. Remove the (16) Philips head black screws on the periphery of the black metal plate supporting the glass

04. Gain access to the inside of your G68 and to the original PSU

05. Remove the (2) screws holding the PSU cover.

06. Note the original the color-coded connecting wires sequence: Yellow (12V), Red, Red (5V), Black, Black (0V), Blue (-12V). They must be rearranged as shown on photo 11

07. Remove the two plastic connectors at each ends of the PSU by using a small plat head screwdriver to press on the tab holding them in place.

08. Unscrew the green/yellow wire connecting the G68 metal case to the PSU and remove the original PSU

09. As you can see, the new PSU is smaller than the original

10. To pull the electrical wires from the plastic connector, pull gently on the wire while pressing on the metal tab accessible from the slot with a small screwdriver: it should come without forcing

11. Note the new wire arrangement as follow: Red, Red (5V), Black, Black (0V), Blue (-12V), Yellow (12V)

12. Next, lift the rubber boot covering the soldered connection of the green/yellow wire and � with a 30W soldering iron � disassemble the connector from the original PSU.

13. Solder it back to the new PSU perforated tab, and after waiting that the solder is cold, cover it back with the protecting rubber boot.

14. Temporarily, I installed a spacer on one of the 4 corner of the new PSU, and I only used one of the original (4) screws to hold the PSU in place, but I would not recommend using just one bolt to secure the PSU. You can easily remove the PSU cage from the G68 chassis, which then permits you to drill four new holes in the cage to hold the PSU securely. You then simply re-attach the cage to the chassis using the original screws.

15. Connect everything back together: the two plastic connectors and the green/yellow cable to the G68 case.

16. Plug it back and power-up to test it. The new PSU comes pre-set at 5.0V and Meridian recommend re-setting this to 5.2V, although this doesn't seems critical.

Only issue I have, is that the level of the Tuner is considerably lower than before� I haven�t had time to investigate yet, but suggestions are welcome.