The Pioneer 531-533-633 are extremely difficult to repair once they break. No factory-authorized service is available today: Pioneer went bankrupt in 2008, and themselves stopped accepting these models for non-warranty repair long before that. Your only repair option is DIY, which I don't recommend. I've been restoring broken Pioneers since 2005, and these three TVGOS models are by FAR the most aggravating. But if you have a lot of time on your hands to tinker, this is the tutorial of what you must do to replace a corrupted HDD:http://www.pioneerfaq.info/english/r...&model=DVR-530
Note there are five parts to the tutorial, navigated on the left hand blue panel with white text indicating "Part 1" etc. Be sure to follow the instructions for the North American models with TVGOS, which are very different from the European (Guide+) and Middle Eastern models. In brief, you must format the boot blocks of a replacement drive with the incredibly fussy TVGOS software, which is unbelievably difficult to install. You need to download the proper software (for 531, or 533/633), boot a PC under Linux, attach the new HDD, and follow the procedure to format the HDD under Linux and install the TVGOS. You then replace the HDD in your 533, and "mate" it to the recorder motherboard using a special Pioneer/Sony "Service Remote" and "Service I.D. Data Disc DVD." The remote can be ordered from various remote vendors for about $30, the service disc can be downloaded with the help of the tutorial website (make a small donation to help fund the site expenses, then ask for assistance).
The "gotcha" is that the whole process almost never "takes" on the first, second, or even third try. I've often had to re-format the new HDD and reinstall the TVGOS five or six times before the 533 finally recognizes and accepts the drive. It can take days or weeks, and some units just refuse to ever recognize a replacement HDD. Pioneer itself got so disgusted with warranty repairs on the 531-533-633 that they turned to a partnership with Sony to rush out the 640 series by the end of the model year: at that point they simply swapped broken 533 recorders for new 640s. rather than expend the labor cost to repair them (many MANY went back for warranty repair: the TVGOS system was very fragile and prone to corrupt the HDD).
Quite frankly, at this point I would not even bother. I won't accept these for repair anymore myself, its just not worth the effort and repaired units all too often fail again within a few months because of Pioneers fundamentally faulty TVGOS engineering. You should go to the WalMart, Target or jandr.com websites and buy a Magnavox MDR513 (320 GB) or MDR 515 (500GB). These are the last of the DVD/HDD models to be sold in USA/Canada, they have modern ATSC 16:9 tuners and most of the features of the 533 (except no ability to rejoin split segments and no TVGOS). More important, they are much more reliable and replacing their hard drives is a simple swap. The Magnavox recorders are just about to go out of production: grab one now before prices skyrocket on the secondary eBay market. J&R sells like-new refurbs
for $169-$198, Target and WalMart sell new sealed units for $198-$248. If you can afford to spend $365, consider the grey-market-import Panasonic EH-69 or EH-59 sold by B&H website.
These have all the features of the 533 plus many more convenience upgrades to the editing interface. However, no tuner and no TVGOS.