This particular model seem to be prone to faulter with its Heater Wire circuitry, unfortunately the Tech manual does not provide much insight into it.
Upon investigation F&P promptly suggested replacement of both pcbs at a steep price totaling £444 + VAT.
Has anybody carried out any research into this problem.
Pls forward your kind solution
Thank you. firstname.lastname@example.org
I've not got a solution Steve, since the MR850 is usually reliable (however prone to being dropped) but I know that there have been a few different software versions applied to the MR850 that have enhanced and modified the way it works, including the self-diagnostics and heater-wire compensation. Have you got the latest manual Steve? Revision "H" I think. Perhaps the error-code is listed in one of the revisions.
Unfortunately I don't have any manuals at hand since I'm on leave but no doubt you've already looked to the device configuration, test-setup, consumables and the heater adaptor wire and dual temp/flow probe as a potential source of problems and substituted them to make certain. Was the problem with dual heater-wire operation or single, intubated or non-intubated, what gas flow-rates, humidity compensation, etc? Will the machine run diagnostic checks 1-6 and can you enter the other diagnostics and configuration menus?
The advice given by the F&P technical support is usually very good and the engineers there are very informative. The MR850 PCBs always come as a pair since they are manufactured and calibrated together I think. The MR850 is usually a reliable piece of kit and the only problems I find are that the heater-wire adaptor socket connections and the dual-flow socket connections sometimes suffer from poor solder joints or the sockets need replacing after drop-damage with plugs being connected plus case changes.
The PCBs are predominantly surface-mount components in any case so if you've eliminated the possibility of heater-wire, dual-temp/flow probe, obvious internal connector or fuse problems and checked the function/suitability of the test-circuit and consumables you're using plus the unit is configured, used and setup correctly for testing purposes, then replacing the PCBs (or decommissioning) may be necessary. Do you use the F&P circuits by the way?
E20 Error code.
If you catch the "E20 error" early you might find C49 and C48 are causing the fault, they are light blue 47uf 50v electrolytic capacitors which sit next to the large reservoir capacitor, probably leaky, usually they are slightly discoloured.
Check associated components as I have seen burnt up transistors and resistors when things have gone too far.
Hope you find this useful.